The present invention relates to disk cartridges wherein a recording/reproducing and spindle-insertion openings are opened/closed by a shutter slidably mounted thereto.
Referring to FIG. 19, a known disk cartridge 101 comprises a disk or disklike recording means 102 such as an optical disk or magneto-optical disk, a main body 103 for rotatably accommodating the disk 102, and a shutter 104 slidably mounted to the main body 103. Recording/reproducing and spindle-insertion openings 105, 106 are formed in one side (upper side as viewed in FIG. 19) of the cartridge main body 103, and a recording/reproducing opening 105 is formed in another side (lower side as viewed in FIG. 19) thereof.
The shutter 104, which serves to open/close the recording/reproducing and spindle-insertion openings 105, 106 of the cartridge main body 103, is formed, e.g. by bending a metal plate in a C-shape. The shutter 104 is slidably mounted to the cartridge main body 103 so as to hold it by a pair of shutter plates 104a, 104b. The shutter plate 104a serves to open/close the recording/reproducing and spindle-insertion openings 105, 106 formed in one side of the cartridge main body 103, whereas the shutter plate 104b serves to open/close the recording/reproducing opening 105 formed in another side thereof.
Since the shutter 104 is formed, e.g. by bending a metal plate in a C-shape, the shutter plates 104a, 104b have a pointed or free end which is warped easily. Particularly, the shutter plate 104a, which needs to open/close both the recording/reproducing and spindle-insertion openings 105, 106, is greater in length than the shutter plate 104b, it is warped more easily. The shutter plate 104b, which only needs to open/close the recording/reproducing opening 105, may be smaller in length.
A shutter guide plate 111 is arranged to prevent a warp of the pointed end of the shutter plate 104a of the shutter 104 and to slide the shutter 104 smoothly. The shutter guide plate 111 is mounted to a shutter-guide-plate mount 112 of the cartridge main body 103, and holds the upper side of a bend 104c of the shutter plate 104a formed at the pointed end thereof to prevent a warp thereof.
The shutter guide plate 111 is made of metal or synthetic resin. Referring to FIG. 20, mounting of the metallic shutter guide plate 111 to the shutter-guide-plate mount 112 is generally carried out in accordance with the method using an adhesive double coated tape 113. Referring to FIG. 21, mounting of the resin shutter guide plate 111 to the shutter-guide-plate mount 112 is generally carried out in accordance with the welding method wherein welded ribs 114 arranged to the shutter guide plate 111 are melted by supersonic vibrations, then solidified.
The known disk cartridge 101 produces the following inconveniences:
First, the method of mounting the metallic shutter guide plate 111 to the shutter-guide-plate mount 112 by the adhesive double coated tape 113 is not excellent in welding efficiency, and causes a cost increase of the disk cartridge 101 due to relatively higher cost of the tape 113.
Second, with the disk cartridge 101 having the resin shutter guide plate 111 mounted to the shutter-guide-plate mount 112 by welded resin, the resin shutter guide plate 111 is broken more easily than the metallic one, and the cartridge main body 103 easily produces a distortion upon welding.
The above inconveniences can be solved by mounting the metallic shutter guide plate 111 to the shutter-guide-plate mount 112 by an adhesive, which may cause, however, a deformation of the shutter guide plate 111 and the cartridge main body 103 due to contraction distortion of the adhesive produced upon curing thereof.
It is, therefore, an object of the present invention to provide disk cartridges which are free of a distortion and deformation produced therein upon mounting, and are excellent in working efficiency and cost performance.